It's unclear to me if this is a matter of:
1. Expression Manager
2.JavaScript on the page (I would like to avoid writing SGQA JS for each distinct question, since they are likely to be hundreds)
3. some RemoteControl API script
4. a custom SQL query that retrieve data directly from the backend, solution that would make me very happy but I suppose it would be difficult to maintain through future updates and would need a custom application converting into final export document.

I apologize in advance if my question is result of a hasty reading of the documentation.
Could you give me some advice?
Thanks in advance!

The administrator has disabled public write access.

JavaScript is currently disabled.Please enable it for a better experience of Jumi.

Sometimes you may be lucky and use the assessment value as question code.
After when you export your results to excel you have the choice beetwen answer text or answer code.
The big limit is that answer code have to be unique (for a same question)

Thanksalot, this sounds good to me; actually I'm using radio buttons.
And the uniqueness of answer code is more a benefit than a limit: I'm not getting the info from the documentation (manual.limesurvey.org/Adding_answers_or_subquestions): has it to be unique throughout all the questions (or their answer set) in the survey?

OK and this is right.
But in this situation your solution doesn't fit well: I couldn't have more than an answer with a specific value.
I couldn't have more answer in different sets with the same value (= code).
Anyway in my specific case I'll go for a workaround - I'll extract the survey results in form of question codes | answer codes and then I'll implement a transcode table where I'll write the tuples answer code | value code.

Anyway, would I have no luck at all using RemoteControl2 API?
I mean, trying to retrieve survey answers in a somewhat conventional manner without bypassing LimeSurvey logic - and trying to keep installation' upgradeability.